by Nebula Haze
Ok, it’s starting to get warm outside. What if you want to harvest a lot of outdoor weed as fast as possible? What if you’re working with a short summer where you live? Perhaps it’s already summer time; do you still have time to grow weed outdoors? Get the answers today!
- Under 2 months → Not enough time to harvest outdoors (time to start an indoor grow)
- 2-3 months left → Grow an autoflower (Gummibears Auto, LSD-25 Auto, White Russian Auto)
- 3+ months left → Grow an autoflower (fastest) or fast photoperiod (Bruce Banner Fast, Guava Root GMO, Gorilla Gas F1)
Grow autoflower strains for an ultra-fast outdoor harvest in as little as 2 months!
Pictured: Rainbow Kush Auto plants on either end, Four Assed Monkey Auto plants in the middle. Masterfully grown by our Home Grow Masterclass student Raymond!
When I started growing in 2008, you had to always plant your cannabis in the Spring and they would not be ready to harvest until late Fall. That’s how traditional (“photoperiod“) strains worked.
Luckily, as a cannabis grower in 2026, you have more outdoor growing options.
There are now many strains, known as autoflower strains, which are ready to harvest as soon as 8 weeks from germination, regardless of when you germinate your seeds. That’s less than 60 days from seed to weed. It’s still mind-blowing to me how fast autoflower can strains sprint to harvest.
Autoflower cannabis strains need as little as 2 months to go from seedlings…
…to a bountiful outdoor autoflower cannabis harvest!
What that means to you: If you’ve got at least two more months of decent weather where you live, you’ve still got enough time to complete an outdoor harvest using autoflower strains. Note: “Decent weather” for growing cannabis plants means the weather is sunny on many days, and not freezing cold or constantly wet.
Fun Fact: I’ve noticed that many fast autoflower strains have “Blueberry” genetics in their history. Someone in the past must have made a fast-flowering Blueberry auto cross!
A lot fast autoflower strains have Blueberry genetics in their history.
What About Photoperiod Strains?
When growing outdoors, photoperiod plants grow buds in the summer and are ready to harvest in the Fall. But even in ideal conditions, the fastest photoperiod strains are usually slower than almost any autoflower strain.
That means if you’re looking for the fastest outdoor harvest, autoflower strains are the best option.
But what about the fastest photoperiod harvest? There are “fast version” photoperiod strains that are ready to harvest a few weeks earlier outdoors, typically in early-to-mid Fall.
Most photoperiod plants (like this Larry Lemon) are not ready to harvest until mid-to-late Fall. “Fast version” strains may be ready in early Fall.
See Recommended Strains for a Fast Outdoor Photoperiod Harvest.
These 10 Autoflower Strains Are Ready to Harvest Outdoors in 2-3 Months
The fastest strains to harvest are autoflower strains. Autoflower strains start making flowers (buds) about a month from germination, and are typically ready to harvest just a month or two after that. The exact amount of time needed depends on the strain.
Most of the following autoflowering strains are ready to harvest 8-10 weeks from germination. 2 months is about as fast as you can harvest with autoflower strains and still get good yields and bud quality.
Note: A little extra time increases bud size and potency. Even with these ultra-fast strains (which do produce great buds in 2 months), you can increase your yields and bud potency further by giving them an extra week or two over the minimum recommended time.
When time is of the essence, the following outdoor autoflower strains serve you well!
Black Cream Auto by Sweet Seeds
Ready to harvest in 60 days from germination, this strain stays on the shorter side. Plants tend to grow one main big bud, and a few smaller side branches. Bud color ranges from regular purple to almost black purple, depending on the particular plant. The smell is sweet and fruity, with earthy notes. Once they’re dried, the dark purple nugs are a unique sight to behold.
Buds have a unique smooth effect that I love from Sweet Seeds strains (whether auto-flowering or photoperiod). Their genetics are originally from Spain and leave you relaxed and floating on a cloud.
Dark purple buds like from some Black Cream Auto are delightful to see on the plant and after harvest!
Here are all the colors of buds you can expect from Black Cream Auto. These plants are extra hardy and can handle some mistakes yet still produce a great harvest. Grown by Santacabrera.
Skunk #1 Auto by White Label
Skunk #1 Auto plants make that old school skunk smell that takes me back to when I first started smoking. Great yields, easy to grow, and ready to harvest in under 60 days. A relaxing strain that is not too intense, making it perfect for social situations or long smoking sessions.
Two Skunk #1 Auto plants grown outdoors (orange cat for protection)
Skunk #1 autos produce big buds outdoors, fast!
Girl Scout Cookies Auto by FastBuds Seeds
I love this autoflower strain for a bunch of reasons. For one, this strain is true-to-its-roots and gives you Girl Scout Cookies buds with the effects you would find in a photoperiod version of the strain. Buds look gorgeous, and feel stronger than the 20% THC. The apparent strength may have to do with the entourage effect and higher levels of d-Limonene in this strain’s buds. Note: D-Limonene is a lemon-smelling terpene that adds to the entourage effect and may make buds feel more relaxing and social.
Plants can get surprisingly tall in a short amount of time. Ready to harvest about 65 days from germination. Prefers higher-than-average nutrient levels in the flowering stage (a plant needs lots of nutrients to grow those huge buds!). Otherwise, plants are hardy and easy to grow.
LSD-25 Auto by FastBuds Seeds
A lot of the fastest autoflower strains are bred by FastBuds, or descended from FastBuds genetics. That’s because this breeder has continuously focused on making strains to produce fast harvests. LSD-25 Auto is a popular choice for growing outdoors because it’s ready to harvest in 60 days from germination, stays small, is easy to grow, and most plants produce bright purple buds.
Outdoor-grown LSD-25 Auto plants typically make bright purple buds. This one was grown by BigBeardy Grows.
Blueberry Auto by Seedsman
I have had consistently great results with most autoflower strains by Seedsman. The seeds germinate well, plants are easy to grow, and bud size and quality are above-average. Their Blueberry Auto is no exception!
These Blueberry Auto plants were grown in a DIY greenhouse (mainly to keep them out of sight), and thrived outdoors.
Blue Cheese Auto by Seed Supreme
This strain tends to grow one main bud, and it can get THICK! Blue Cheese Auto is specifically resistant to mold or bud rot, so it can handle higher humidity levels than many other strains. Great if you tend to have a lot of wet days or high humidity where you live. Ready to harvest in about 70 days from germination.
Blue Cheese Auto plants grow well outdoors, even if the environment isn’t perfect.
Blue Dream Auto by Seed Supreme
Needing 70 days from seed to harvest, Blue Dream plants tend to be easy to grow with excellent yields and bud effects.
Blue Dream Auto plants tend to grow themselves.
Some of these strains take a little longer, but are still very fast and reward you with bigger yields than the fastest autoflower strains.
Mint Jelly Auto by Humboldt Seed Company
This strain is an autoflowering version of the popular Mint Cake strain, but it may have turned out even better than the original. It has a THC level of up to 27% and a peppermint and cake flavor. It grows well outdoors, and is ready to harvest about 70-80 days after germination.
Mint Jelly Auto produces up to 27% THC – one of the most potent outdoor autoflowering strains available!
Cream Cookies Auto by Fastbuds Seeds
This strain is considered to be an Indica-dominant strain (its “body high” is greater than its “head high”) with high resin production. It has a THC level of a little over 20% and buds have a caramel and creamy flavor. It grows well outdoors and is ready about 10 weeks from germination.
Most autoflower cannabis plants, including Cream Cookies Auto, tend to stay on the smaller side, unless marked as XL
Planet of the Grapes Auto by Ethos Genetics
Easy to grow, good yields, smells great, STRONG bud effects. May be even stronger than Mint Jelly Auto in some cases. Tends to take a bit longer than most autos (up to 90 days) and gets bigger (up to 2-3 feet tall) but will reward you for your patience with amazing yields of top-quality buds. When growing outdoors, you want to plant this strain a full 3 months before it gets cold or rainy outside where you live.
Planet of the Grapes Auto grows with a natural bushy structure and buds are amazing.
Kushberry Moonrocks Auto by MSNL
Easy to grow, hardy enough to grow in hot or arid climates, and great yields make this a gem in the outdoor autoflowering strain world. Ready to harvest about 2.5 months from germination. I absolutely love the photoperiod version of this strain, and the autoflowering strain lives up to the same standard of bud quality. Truly an example of getting photoperiod buds in autoflowering form.
Kushberry Moonrocks Auto cannabis bud quality is in a league of its own.
Grease Gun Auto by Atlas Seed
This strain produces the best bud quality, resin production, and potency if you allow buds to continue to mature until a full 12 weeks from germination, though it can be harvested a week or two earlier in a pinch.
Here’s an outdoor Grease Gun Auto grown by SkunkSquatch: “Plant is grown in a 7 gallon grow bag about 22 inches tall.”
Grease Gun Auto by Atlas Seed does well in outdoor conditions and grows sparkly buds dripping in resin.
Zkittlez Auto by Seedsman
Extremely easy to grow indoors or out, this strain does take a bit longer than most others on this list, needing almost 90 days from seed to harvest. Yet still faster than any photoperiod strain. For your patience, Zkittlez Auto plants reward you with huge yields of sweet-smelling buds covered in trichomes.
Zkittlez Auto buds produce lovely “chill” effects, and smell delicious.
Auto Duck by Dutch Passion
“Duck” strains (also called “Ducksfoot” strains) look different from other cannabis plants. Unlike typical cannabis leaves, the leaves of these strains are the shape of a duck’s foot. This is due to a natural mutation that an enterprising cannabis grower noticed and bred into a strain. As a result, these plants don’t look as much like cannabis plants to most eyes even after buds start growing. That makes these strains a coveted choice for outdoor growers looking for a little extra stealth.
This strain takes a full 3 months outdoors from seed to harvest, but rewards you with excellent buds. This particular version of Duck has been crossed with a high quality White Widow, giving you White Widow buds from a duck leaf cannabis plant.
Auto Duck by Dutch Passion is a cannabis strain that grows unique duck’s foot-shaped leaves. Stealthy!
Check out those leaves up close.
A Ducksfoot strain has less of an overall “cannabis” aesthetic.
What About Photoperiod Strains?
If you’re pressed for time before cold weather arrives, or just want the fastest outdoor harvest possible, then photoperiod strains aren’t your best bet. Even the fastest photoperiod strains aren’t ready to harvest as fast as almost any auto-flowering strain.
Most photoperiod strains are ready to harvest in mid-to-late Fall
While autoflower plants are ready to harvest based on their age, photoperiod plants go through their life cycle based on the season. They start producing buds in response to long nights, which means photoperiod strains typically start making buds in mid-to-late summer. Buds continue to mature until plants are ready to harvest in Fall.
Think of it as if a photoperiod cannabis plant is “trying” to finish making buds before winter comes.
Most photoperiod plants (like this Larry Lemon) are not ready to harvest until mid-to-late Fall. Notice how the leaves in the background have changed color.
“Fast” photoperiod strains are ready to harvest in early-to-mid Fall
When a photoperiod strain is “fast” that means it tends to be ready to harvest a bit earlier in the Fall season. However, there is no photoperiod strain that is naturally ready to harvest in summer. Photoperiod plants are “trying” to time their harvest to happen right before winter. If you want an outdoor summer harvest, you need to choose auto-flowering strains.
You need an auto-flowering strain, like this Bloody Skunk Auto, to achieve a harvest in summer.
Photoperiod plants are very sensitive to time of year
An odd quirk is that if you plant photoperiod seeds outside too early in the spring, the nights will be long enough to cause them to start making buds immediately. However, since the days are getting shorter at that time of year, the plants quickly revert back to the vegetative stage, buds die, and the plant then goes through its regular life cycle, becoming ready to harvest in the Fall.
On the other hand, with an auto-flowering plant, this is not a consideration. Just put the plants outside when you know you have 2-3 months of good weather.
Photoperiod plants may “re-veg” if you put them outside too early.
Remember: Whether you plant photoperiod seeds outside in the Spring or Summer, the buds will be ready to harvest in the Fall.
Photoperiod strains aren’t the best choice for late planting
Photoperiod strains grow best outdoors when placed outside in late Spring. If you plant photoperiod seeds too late, the buds might not be ready to harvest in time, even if you’re growing a Fast Photoperiod strain. Why? Let’s look at the life of a photoperiod plant to see why they need more time than you might think.
A photoperiod seedling needs a certain amount of maturity before it can start flowering (making buds). Typically, most photoperiod plants do not start flowering until at least 3-4 weeks old (later for some strains), even if you plant it later in the season when normally a plant would start flowering. So let’s say you’ve only got 3 months left before it gets cold or rainy in your climate. That means you need a photoperiod strain with a 2 month flowering period or shorter, because your plant won’t start flowering for the first month. And that’s if everything goes as planned.
Start seedlings indoors to help give them a fast start.
That’s why it’s recommended to get a photoperiod strain with the absolute shortest flowering period when planting later in the season. This just helps speed everything up and ensure your buds are mature and ready to harvest before it gets cold.
There are several “Fast” photoperiod strains, which have 6-8 week flowering periods in good conditions. These can shave off a few weeks from the flowering stage, but you’re still looking at a 3+ month grow from start to finish outdoors. If you’ve got less time than that, I highly recommend going with autoflowering strains!
“Fast” strains are your best bet for photoperiods with late outdoor planting.
Another tip for growing outdoors is to make sure to start your seeds indoors, so they get a headstart and are strong enough to start growing fast and healthy as soon as they’re put outdoors. Take great care of these seedlings and pay close attention to them from the beginning. Be careful not to overwater them. And when you put them outside, ensure they get lots of sun.
Outdoor Late-Planting Photoperiod Tips
- Grow a “Fast” Photoperiod Strain – Get a strain with a 6-8 week flowering period (as fast as it gets for photoperiod strains).
- Start Indoors – Give your photoperiod seedlings a head start by giving them perfect conditions for the first few weeks of life.
- Lots of Sun – It’s especially important to make sure your late-planted cannabis plants get a lot of light. Light is food for plants!
- Don’t Overwater – Overwatering is one of the most common ways to slow down a cannabis plant.
Learn how to grow great cannabis outdoors.
“Fast” Photoperiod Strains – Ready to harvest in early-to-mid Fall. For an earlier harvest, grow an autoflowering strain!
Note: Even if you plant these strains outdoors very late in the season, fast photoperiod strains need at least 3 months from germination before buds are ready to harvest.
Bruce Banner Fast Version by Seed Supreme
Bruce Banner is an epic strain, and this is the faster flowering version. The quality of buds is the same, though with a shorter flowering period it tends to have slightly lower yields than if you grew the non-fast version. Extremely potent (over 25% THC) so these buds are not for the faint-hearted.
Bruce Banner Fast by Seed Supreme does well in outdoor conditions and grows sparkly buds dripping in resin.
Northern Lights Fast Version by Seed Supreme
This strain is a good choice for a stealth grow because it tends to grow more short and bushy (won’t grow over your fence), and doesn’t stink up a storm like many other photoperiod strains. Tends to be a relatively hardy and forgiving plant, and can handle colder climates better than most strains on this list. The reward is sparkly buds with a nice smooth smoke.
Northern Lights Fast by Seed Supreme does well in outdoor conditions and grows sparkly buds that smell fresh with a touch of incense.
Blue Princess Fast Version by Homegrown Cannabis Co.
This is a Blueberry crossed with a Cinderella strain (hence “Blue Princess”), and the fast version has proven to perform well outdoors and still reward you with an ultra-fast harvest. A great strain for those who suffer from anxiety, as the higher CBD levels help provide a relaxing soothing effect, and overall is known as a “smiley” strain.
Blue Princess Fast by Homegrown Cannabis Co. is well-suited to outdoors and grow dense, professional looking buds.
Frisian Dew by Dutch Passion
Although not a “fast type” strain, any list of great outdoor cannabis strains has to include Frisian Dew. It is the quintessential outdoor strain, being developed specifically to thrive in non-ideal outdoor environments (especially colder climates), yet still produce a great harvest. Buds are typically purple, plants are resistant to pests, cold, high humidity, and other common stresses.
A great choice for growers at northern latitudes. It tends to be ready to harvest earlier than most other photoperiod strains.
Frisian Dew was specifically bred to thrive outdoors in northern climates.
A closeup of Frisian Dew buds. Beautiful!
Ready to Plant for a Late Summer Cannabis Harvest?
If you’re going to grow outdoors and it’s already getting late in the season, then you need to grow a fast autoflowering strain. These strains need as little as 2 months from seed to harvest. If you’ve got more than 3 months, then an early-finishing photoperiod strain can also work.
What this means to you: As long as you have decent weather for the next few months, you have enough time to plant one of the recommended cannabis seeds outdoors and still get a good summer harvest.
Remember, with outdoor plants, give them as much direct light as possible every day, and pay attention to the weather. If it’s going to be bad weather, do what you can to protect your plants from the elements. Here’s a full guide on how to grow cannabis outdoors.
About the Author: Nebula Haze
Nebula Haze is a dedicated cannabis enthusiast and co-creator of GrowWeedEasy.com, your resource for every aspect of cannabis cultivation. With years of hands-on experience growing cannabis at home, Nebula uses her passion to simplify the grow process so anyone can achieve amazing yields and bud quality at home. Her in-depth yet simple tutorials make learning to grow weed easy and fun, the way it should be!
Nebula Haze wishing you many abundant harvests!
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